JS Objects as Arguments to NativeFunctions

AaronLS · December 2, 2021, 5:04am

Hello, I have started using Uno.Wasm.Bootstrap to generate WASM in order to run C# client side. I.e. I’m not using the full Uno UI platform.

I was looking at the Fuse Native JS Modules examples: Creating native JavaScript Modules in Uno - Fuse Documentation

In the example the SendMessage function receives the message in the object[] array and is cast to a string.

What if I want to be able to pass a more complex javascript object as an argument? I.e. a javascript object that has properties and methods.

Is it possible to do something like this so that I can have a handle to a JS object and interact with it?

object[] SendMessage(Fuse.Scripting.Context context, object[] args)
    {
        var jsObject = args.First() as Fuse.Scripting.Object;
        jsObject.CallMethod("someJsIObjectMethod", 123);
    }

Hassan_M · December 2, 2021, 2:36pm

I think it can be done, take a look at this source code for reference:

github.com

fuse-open/fuselibs/blob/c66007f5133c2c46a7293acb948b23c208db828e/Source/Fuse.Scripting.JavaScript/Observable.uno#L161

    
      
          				Scripting.Object Object;
          				readonly object[] NewValues;
          				readonly int Origin;
          
          

          
				public void Perform(Scripting.Context context)
          				{
          					for (int i = 0; i < NewValues.Length; i++)
          						NewValues[i] = context.Unwrap(NewValues[i]);
          
          
					Object.CallMethod(context, "replaceAllWithOrigin", context.NewArray(NewValues), Origin);
          				}
          			}
          
          
			void ISubscription.ReplaceAllExclusive(IArray newValues)
          			{
          				var arr = new object[newValues.Length];
          				for (int i = 0; i < arr.Length; i++)
          					arr[i] = newValues[i];
          
          
				var op = new ReplaceAllExclusiveOperation(_om._worker, _om.Object, arr, _origin);

and:

github.com

fuse-open/fuselibs/blob/c66007f5133c2c46a7293acb948b23c208db828e/Source/Fuse.Scripting.JavaScript/FuseJS/Observable.js#L998

    
      
          	this._values = [value];
          	this._queueMessageExclusive([this, "set", origin, value], exclude);
          };
          
          
Observable.prototype.setValueWithOrigin = function(value, origin)
          {
          	this._values = [value];
          	this._queueMessage(this, "set", origin, value);
          };
          
          
Observable.prototype.replaceAllWithOrigin = function(values, origin)
          {
          	this._values = values;
          	this._queueMessage(this, "newAll", origin, values);
          }
          
          
/*
          	Gets or sets the (first) value of the observable.
          	This property is mainly for use with for sigle-valued observables.
          	If the observable contains multiple values, this property only
          	gets or sets the first value.

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JS Objects as Arguments to NativeFunctions

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